Grant: Subatomic Physics Envelope - Project

HELIX (the High -Energy Light Isotope eXperiment) is an instrument designed to measure the mass, charge and energy of cosmic rays at an altitude of 35 km using a stratospheric balloon provided by NASA. Cosmic rays are highly energetic particles originating from outside of the solar system. Despite their well-recognized importance in Galactic dynamics and the early history of particle physics, little is known about their origin. Because they are charged and, therefore, deflected by magnetic fields, understanding their origins requires precise measurements and models for producing and propagating cosmic rays. In the last decade, measurements of cosmic rays have seen revolutionary improvements, with several major space--based instruments observing cosmic rays with unprecedented precision. These measurements discovered many new characteristics in the cosmic ray flux, including an unexpected excess of positrons. To understand the nature of cosmic rays, it is essential first to better understand the propagation of cosmic rays. This is because the influence of different source populations, different acceleration processes, and the effects of exotic particles, such as dark matter, must all be disentangled from the effects of propagation through the Galaxy. The main objective of HELIX is to make significantly improved measurements of the beryllium--10 (Be--10) isotope, which is the key to improving current propagation models. Be--10 decays with a known half--life of 1.4 million years, comparable to the lifetime of cosmic rays in the Galaxy. By comparing the flux of Be-10 with that of Be-9, a stable isotope produced through similar processes with Be-10, we can study the cosmic rays' propagation within the Galaxy. The HELIX collaboration plans for multi--stage developments of magnetic spectrometers to achieve a mass resolution of ~3% in the energy range of 1 GeV/n to 10 GeV/n for the first time. The first stage of HELIX comprises a 1 Telsa superconducting magnet, a drift chamber tracker, a time--of-flight detector, a scintillating fibre hodoscope, and a ring imaging Cherenkov detector (RICH). The collaboration is preparing for a seven--day flight in 2024 summer from Kiruna, Sweden, to the Canadian Arctic. After payload recovery, we will work toward having a longer circumpolar flight over Antarctica in the 2026-2027 astral summer. The payload for the Antarctic flight will include new or upgraded detector systems: a layer of silicon strip detector and a dual-radiator RICH to improve mass resolution for higher energies. This proposal requests funding for Canadian research activities on HELIX, including support for flight, recovery, refurbishment of the payload, data analysis, and detector developments. HELIX provides excellent training for HQPs on hardware and software relevant to other subatomic experiments and the aerospace industries.